A recent report by the Institute of Medicine (2003) synthesized a large body of empirical research evidence, acquired over more than a decade, illustrating disparities in health care, diagnosis, and treatment. While disparities have been extensively documented and found to be associated with numerous patient characteristics, including age, race, and sex, there is little to illuminate the mechanisms through which these healthcare disparities arise. The proposed study aims to fill that gap by systematically varying key patient and physician characteristics and studying the content and process of physician-patient interactions for older patients with symptoms of depression and early stage coronary heart disease (CHD). This research builds on earlier work by linking patient and physician variables with process and content, as well as clinical decision making outcomes. 120 primary care physicians will be recruited to see two 'standardized' patients representing depression and CHD in actual medical visits. The central hypothesis for the proposed research is that patient and physician characteristics, individually and in combination, lead physicians to elicit and offer differing kinds of information, thereby producing differences in diagnostic and treatment recommendations for older patients with varying profiles. The proposed research by a multidisciplinary team uses an experimental design to investigate systematically the effects of three patient factors (gender, race, and level of assertiveness) and three physician factors (gender, race, and years of clinical experience) on the process and content of the interaction and on physicians' clinical decisions. Standardized patients varying on all three characteristics will be recruited and carefully trained to simulate a consistent symptom presentation for each of the two conditions. The visits will be audiotaped and coded using the Roter Interaction Analysis System (Roter, 1977; Roter and Larson, 2002) and the Multi Dimensional Interaction Analysis (Greene et al, 1987; Charon et al, 1991). Structured medical record review will be conducted to assess physicians' diagnosis and treatment recommendations. The objective of the proposed research is to identify how the communication process mediates the relationship among patient factors, physician factors, and diagnosis and treatment of these two common clinically significant conditions. The findings from this research will help identify aspects of the medical interaction that are priorities for improvement in order to optimize healthcare outcomes for the elderly. The results of this research will inform the development of targeted education and intervention strategies to improve the quality of care of older patients. [unreadable] [unreadable]